The standard costs and actual costs for factory overhead for the manufacture of 2,800 units of actual production are as follows: Standard Costs Fixed overhead (based on 10,000 hours) 3 hours per unit @ $0.72 per hour Variable overhead 3 hours per unit @ $2.08 per hour Actual Costs Total variable cost, $17,900 Total fixed cost, $7,900 The amount of the fixed factory overhead volume variance is Oa: $922 favorable Ob. 5922 unfavorable OG 50 Od: 51.152 unfavorable